Air bearing for a head to provide reduced cross-curve sensitivity

ABSTRACT

An air bearing for a slider including cooperating raised bearing surfaces or portions along a trailing edge portion of the slider. The cooperating raised bearing surfaces or portions are formed on a stepped bearing surface which is elevated above a recessed bearing surface. The cooperating raised bearing surfaces or portions form raised rails or rails portions or a raised center pad or raised center pad portion on the stepped bearing surface to reduce cross curve sensitivity.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from U.S. ProvisionalApplication No. 60/387,978 filed on Jun. 12, 2002 and entitled “AIRBEARING DESIGN TAILORED FOR REDUCED SENSITIVITY TO CROSS CURVE”.

FIELD OF THE INVENTION

[0002] The present invention relates generally to data storage devices,and more particularly but not by limitation to an air bearing design fora data storage device.

BACKGROUND OF THE INVENTION

[0003] Data storage devices store digital information on a disc orstorage media. Heads read data from or write data to the data storagedisc. Heads include transducer elements, such inductive,magneto-resistive and magneto-optical transducer elements for read-writeoperations. Heads are coupled to an actuator assembly via a headsuspension assembly and the actuator assembly is energized to positionthe heads relative to selected data tracks for read-write operations.The head suspension assembly includes a load beam which supplies a loadforce to the head at a load or gimbal point. The head is coupled to thesuspension assembly or load beam through a gimbal spring so that thehead pitches and rolls relative to the load or gimbal point to followthe contour of the disc or data storage surface.

[0004] Transducer elements of the head are carried on a trailing edge ofan air bearing slider for proximity, near proximity or near contactrecording. The air bearing slider includes at least one raised bearingsurface and at least one recessed bearing surface. Rotation of the discor storage medium provides an air flow along the air bearing surface ofthe slider to provide a hydrodynamic lifting force which is countered bythe load force to define in part a fly height for the slider forread-write operations. Head-disc spacing or fly height is controlled inpart by air bearing pressurization, where as the fly height decreases,air bearing pressure increases and air bearing pressure decreases as thefly height increases to provide a relatively stable fly height. Arealdisc drive density is increasing requiring lower fly heights orhead-disc spacing between the transducer elements at the trailing edgeof the slider (or pole tip fly height (PTFH)) and the disc surface fordesired read-write resolution and clarity. The lower fly heights demandbetter control over pressurization of the air bearing surfaces.

[0005] Variations in the relative linear velocity of the rotating discbetween the inner and outer diameters of the disc and variations in theskew angle between the head and disc relative to the inner and outerdiameters of the disc can affect air bearing pressurization or flyheight of the slider based upon radial position of the head. Heads arefabricated by a wafer fabrication process which can introduce a crosscurve between opposed sides, along a cross dimension or width, of theslider or head. The cross curve can affect pressurization or thepressure profile of independent bearing surfaces across the crossdimension or width of the head or slider. Embodiments of the presentinvention provide solutions to these and other problems, and offer otheradvantages over the prior art.

SUMMARY OF THE INVENTION

[0006] The present invention relates to an air bearing for a sliderincluding cooperating raised bearing surfaces or portions along atrailing edge portion of the slider. The cooperating raised bearingsurfaces or portions are formed on a stepped bearing surface which iselevated above a recessed bearing surface. In embodiments of the presentinvention, cooperating raised bearing surfaces or portions form raisedrails or rails portions or a raised center pad or raised center padportion on the stepped bearing surface to reduce cross curvesensitivity. Other features and benefits that characterize embodimentsof the present invention will be apparent upon reading the followingdetailed description and review of the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is perspective illustration of a data storage device.

[0008]FIG. 2 is a schematic elevational view of a head suspensionassembly having a head or slider coupled thereto.

[0009]FIG. 3 is a schematic illustration of a head or slider coupled toa head gimbal assembly.

[0010]FIG. 4 is a diagrammatic illustration of a head or slider relativeto a disc surface for read-write operations.

[0011]FIG. 5 is a schematic illustration for wafer fabrication of heads.

[0012]FIG. 6 schematically illustrates a slider bar and a cross curvefor sliders therealong.

[0013] FIGS. 7-10 schematically illustrate a prior art embodiment of anair bearing surface of a head or slider.

[0014]FIG. 11 schematically illustrates the slider of FIGS. 7-10 havinga cross curve.

[0015] FIGS. 12-13 schematically illustrate an air bearing embodimenthaving multiple raised bearing surfaces on an integral stepped bearingsurface.

[0016] FIGS. 14-15 schematically illustrate an alternate air bearingembodiment having multiple raised bearing surfaces on an integralstepped bearing surface.

[0017] FIGS. 16-19 schematically illustrate an air bearing embodimenthaving multiple raised bearing surfaces cooperatively formed along atrailing edge portion of a slider.

[0018] FIGS. 20-21 schematically illustrate an air bearing embodimentincluding cooperating raised bearing portions formed on a steppedsurface along a trailing edge portion of a slider.

[0019] FIGS. 22-23 schematically illustrate an air bearing embodimenthaving multiple raised bearing portions cooperatively formed along atrailing edge portion of a slider.

[0020] FIGS. 24-25 schematically illustrate an air bearing embodiment ofthe prior art.

[0021] FIGS. 26-27 schematically illustrate an air bearing embodimenthaving multiple cooperating raised bearing surfaces formed along atrailing edge portion of a slider.

[0022]FIG. 28 comparatively illustrates PTFH for various cross curves(cc) for the sliders of FIGS. 24-25 and FIGS. 26-27.

[0023] FIGS. 29-30 schematically illustrate an air bearing embodimentincluding multiple cooperating raised bearing surfaces formed along atrailing edge portion of a slider.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0024]FIG. 1 is a perspective illustration of an embodiment of a datastorage device 100 in which embodiments of the present invention areuseful. Device 100 includes at least one data storage disc 102rotationally (as illustrated by arrow 104) coupled to a base chassis 106by a spindle motor (not shown). Heads 108 are coupled to an actuatorassembly 110 as shown. A voice coil motor 112 is coupled to the actuatorassembly 110 and is operational to position the heads 108 relative toselected data tracks between an inner diameter 114 and an outer diameter116 of the disc 102 for read-write operations through interface with ahost system (not shown).

[0025] The head 108 includes a slider 120 having an air bearing surface122, a leading edge 124 and a trailing edge 126 as shown in FIG. 2.Rotation of the disc 102 provides an air flow along the air bearingsurface 122 of the slider from the leading edge 124 to the trailing edge126 for operation. In the illustrated embodiment, transducer elements128 (illustrated schematically) are fabricated proximate to the trailingedge 126 of the slider 120. Transducer elements include, but are notlimited to inductive, magneto-resistive, tunneling magneto-resistive andmagneto-optical transducer elements.

[0026] As shown in FIGS. 2-3, heads 108 are coupled to an actuator arm130 of the actuator assembly 110 through a head suspension assembly 132including a load beam 134 and a gimbal spring 136. As shown, the loadbeam 134 is adapted to supply a load force to the slider 120 at a loadpoint 138 (shown in FIG. 3) which is opposed to a hydrodynamic liftingforce of the air bearing surface 122 of the slider 120 to define in parta fly height for the slider above the disc surface. The slider isflexibly coupled to the gimbal spring 136 to pitch about a pitch axis140 and roll about a roll axis 142 between opposed sides 144, 146 of theslider. The slider pitches and rolls relative to the gimbal or loadpoint 138 to follow the contour of the disc surface for read-writeoperations.

[0027] As illustrated in greater detail in FIG. 4, for operation,transducer elements 128 are spaced from the disc surface 148 to providea head-disc spacing or PTFH 150 between the transducer elements 128 andthe disc surface 148 for read-write operations. Areal disc drive densityis increasing, reducing head-disc spacing parameters for desiredread-write resolution and clarity. The reduced spacing or PTFH requiresbetter fly height control or tolerance between the transducer elementsand the disc surface.

[0028] Heads are typically fabricated by a wafer fabrication process. Inthe embodiment illustrated in FIGS. 5-6, a plurality of transducerelements 128 are deposited on a wafer 152. Slider bars 154 are dicedfrom the wafer 152 as shown in FIG. 6. Air bearing surfaces 122 for aplurality of sliders 120-6 are formed on the slider bar 154. The sliderbar 154 is lapped to provide a desired stripe height for the transducerelements 128 and individual sliders 120-6 are sliced from the slider bar154. As shown a thickness dimension 160 of the slider bar 154 or wafer152 forms a longitudinal length of the sliders 120-6 between the leadingand trailing edges of the sliders 120-6 and a cross dimension 162 of thesliders 120-6 is formed along a longitudinal length of the slider bar154.

[0029] As shown, the fabrication process can introduce a cross curve orbow 168 along the cross width or dimension 162. The cross curve 168 canaffect a pressure profile of the air bearing surface of the slider. Airbearing surfaces 122 of sliders are designed to provide an optimumpressure profile to control fly height of the slider 120. The crosscurve 168 and the radial position of the head relative to the disc canintroduce variations in the pressure profile of the slider interferingwith optimum fly height control. For example, the pressure profile ofindividual sliders can vary due to manufacturing processes and crosscurve 168 of the slider.

[0030] FIGS. 7-10 illustrate an embodiment of a multi-tiered air bearingsurface for a prior art slider 120-7 where like numbers are used torefer to like parts in the previous FIGS. In the illustrated embodiment,the slider 120-7 includes a slider body 170-7 including a leading edgeportion 172, an intermediate portion 174 and a trailing edge portion176. The illustrated slider 120-7 includes muti bearing surface tiersincluding stepped bearing surfaces elevated above a recessed or etchsurface and raised bearing surfaces elevated above the stepped bearingsurfaces. In the particular illustrated embodiment shown in FIGS. 7-8,the leading edge portion 172 includes raised bearing surfaces 180-1,180-2 formed along opposed rails 182, 184 and stepped bearing surface186-1 elevated above the recessed or etched surface.

[0031] As illustrated in FIGS. 7 and 9, the intermediate portion 174includes stepped bearing surfaces 186-2, 186-3 formed along rails 182,184. The stepped bearing surfaces 186-2, 186-3 include a recessed oretched cavity 188 forming a recessed or etched surface along rails 182,184. As illustrated in FIGS. 7 and 10, the trailing edge portion 176includes opposed raised bearing surfaces 180-3, 180-4 formed on steppedbearing surfaces 186-2, 186-3 along opposed rail 182, 184 and raisedbearing surface 180-5 form on stepped bearing surface 186-4 forming acenter pad 190 of the slider elevated above the etched or recessedregion 192 forming the recessed or etched surface portions of theslider. As shown in FIG. 10, the raised bearing surfaces 180-3, 180-4 ofrails 182, 184 and the raised bearing surface 180-5 of center pad 190are separated by the recessed surface or region 192 to form independentbearing surfaces.

[0032]FIG. 11 illustrates a cross profile of the trailing edge portionof the slider 120-7 embodiment of FIGS. 7-10. The raised bearingsurfaces 180-3, 180-4, 180-5 of rails 182, 184 and center pad 190 alongthe trailing edge portion of the slider provide active bearing surfacesto control fly height or spacing for the transducer elements PTFHrelative to the disc surface. In particular, each of the independentraised surfaces of the rails 182, 184 and center pad 190 contribute tofly height control. As illustrated in great exaggeration in FIG. 11 fora slider having a cross curve 168 relative to reference 200, the raisedbearing surfaces of the rails 182, 184 and center pad 190 are offsetrelative to one another along the cross dimension 162. The offsetrelation of the raised bearing surfaces as shown affects the pressureprofile along the air bearing surface and fly height control.

[0033] The present invention provides an air bearing slider havingmultiple cooperating bearing surfaces to reduce the affect of crosscurve on air bearing pressurization or pressure profile, or reducecross-curve sensitivity. FIGS. 12-13 schematically illustrate anembodiment of a slider 120-12 of the present invention where likenumbers are used to refer to like parts in the previous FIGS. In theillustrated embodiment shown, the slider 120-12 includes spaced raisedbodies 210, 212 formed on a trailing edge portion 176-12 of the sliderto form a plurality of raised bearing surfaces 214-1, 214-2. The raisedbearing surfaces 214-1, 214-2 are active bearing surface and not pads orprojections for stiction control for contact starts and stops.

[0034] As shown, the spaced raised bodies 210, 212 are formed on astepped portion 216 elevated above a recessed surface 218 of the sliderbody 170-12. The stepped portion 216 is elevated above the recessedportion 218 to form a stepped bearing surface 220 and the raised bearingsurfaces 214-1, 214-2 are elevated above the stepped bearing surface220. As shown, the raised bodies 210, 212 are cooperatively formed onthe stepped portion 216 to provide cooperating active or raised bearingsurfaces 214-1, 214-2. The cooperating raised or active bearingssurfaces 214-1, 214-2 are not separated by a recessed surface or regionand are cooperatively pressurized relative to the stepped bearingsurface 220 to reduce cross curve sensitivity since milling deformationsfor the air bearing structure deform in one plane as opposed todeforming in multiple planes.

[0035] In an alternate slider 120-14 embodiment illustrated in FIGS.14-15, the slider 120-14 includes raised bodies 222, 224, 226 formed ona stepped bearing portion 228 along a trailing edge portion 176-14 ofthe slider body 170-14. As shown in FIG. 15, raised bodies 222, 224, 226form raised bearing surfaces 230-1, 230-2, 230-3 elevated above astepped bearing surface 232 formed by the stepped bearing portion 228.The stepped bearing surface 232 is elevated above a recessed bearingsurface 234 as shown. As shown raised bodies 222, 224, 226 arecooperatively formed on the stepped bearing portion 228 to providemultiple raised or active bearing surfaces 230-1, 230-2, 230-3 along thetrailing edge portion which are not separated by recessed surfaces orportions to reduce cross curve sensitivity as previously described. Inthe illustrated embodiment of FIGS. 12-13, raised bodies 210, 212 formraised bearing rails and in the illustrated embodiment of FIGS. 14-15raised bodies 220, 226 form raised bearing rails and raised body 224forms a raised center pad for operation.

[0036] FIGS. 16-19 illustrate an alternate slider embodiment includingcooperating raised or active bearing surfaces along a trailing edgeportion of the slider body. The slider body or air bearing includes astepped bearing surface elevated above a recessed bearing surface andraised bearing surfaces elevated above the stepped bearing surface. Inparticular, as shown in FIGS. 16-17, the leading edge portion 172-16includes a leading edge stepped bearing surface 240-1 and raised bearingsurface 242-1. As illustrated in FIGS. 16 and 18, the trailing edgeportion 176-16 includes raised bodies 244, 246, 248 formed on a steppedbearing portion 250. As illustrated in FIG. 18, the raised bodies 244,246, 248 form raised or active bearing surfaces 242-2, 242-3, 242-4along the trailing edge portion 176-16 and the stepped bearing portion250 forms stepped bearing surface 240-2 to pressurize the multipleraised bearing surfaces 242-2, 242-3, 242-4. As shown, the raisedbearing surfaces 242-2, 242-3, 242-4 along the trailing edge portion areintegral with the stepped bearing surface 240-2 to cooperativelypressurize the active or raised bearing surfaces without interveningcavities or recessed surfaces.

[0037] In the illustrated embodiment, the stepped bearing portion 250and raised bodies 244, 246, 248 formed thereon are formed along a centerportion 252 between opposed side portions 254, 256 of the slider body170-16. As shown, the raised bodies 244, 246, 248 form active bearingsurfaces 242-2, 242-3, 242-4 along the center portion 252 spaced fromthe opposed sides 144-16, 146-16 of the slider body to reduce thedistance of the active bearing surfaces from a center portion of theslider body to reduce sensitivity to cross curve.

[0038] In the embodiment shown, the raised bodies 244, 246 form raisedbearing rails and the raised body 248 forms a raised center pad. Theraised bearing rails are positioned closer to the raised center pad thanin prior art embodiments to provide cooperating bearing surfacespositioned close to a center portion of the slider body to reducesensitivity to cross curve. The position of the raised bearing railsrelative to the raised center pad can be optimized to provide desiredroll stiffness based upon the particular structure of the slider. In theillustrated embodiment, the raised bodies 244, 246 or bearing rails aregenerally “U” shaped, although application is not limited to anyparticular shape.

[0039] In the illustrated embodiment, the stepped bearing portion 250extends from the raised bearing surface 242-1 proximate to the trailingedge. As shown in FIGS. 16 and 19, the air bearing includes recessedcavities 258, 260 on opposed sides of the stepped bearing portion 250forming recessed surfaces of the air bearing. The stepped bearingportion 250 includes a recessed cavity 264 along a length thereof toform a recessed bearing surface of the slider. In the particularembodiment illustrated, the recessed cavity 264 includes a steppedportion 266 forming a stepped bearing surface 240-3 as shown in FIG. 19.The stepped surface portions of the illustrated air bearing provide abetter imaging surface for air bearing modeling using digital scanningor imaging techniques over prior art embodiments having recessed bearingsurfaces. The illustrated embodiment includes stepped rail portions 268,269 along opposed sides 144-16, 146-16 of the slider.

[0040] FIGS. 20-21 schematically illustrate an alternate embodiment ofthe present invention where like numbers are used to refer to like partsin the previous FIGS. As shown, the slider 120-20 includes a raised body270 formed on and elevated above stepped bearing portion 272 on atrailing edge portion 176-20 of the slider body. The stepped bearingportion 272 is elevated above a recessed bearing surface or region 274so that the raised body 270 forms a raised bearing surface 276 elevatedabove a stepped bearing surface 278 and the stepped bearing surface 278is elevated above the recessed bearing surface 274. The raised body 270includes opposed raised rail portions 280, 282 and a raised centerportion 284 to cooperatively formed raised bearing rails and a raisedcenter pad on the trailing edge portion of the slider body withoutintervening recessed surfaces or regions as previously described.

[0041] As illustrated in the embodiment of FIGS. 20-21, the raised railportions 280, 282 include a leading edge 288-1, 288-2 and a trailingedge 290-1, 290-2 and the raised center portion 284 includes a leadingedge 292 and trailing edge 294. As shown, the leading edges 288-1, 288-2of the raised rail portions 280, 282 are closer to the leading edge124-20 of the slider body than the leading edge 292 of the raised centerportion 284 and the trailing edges 290-1, 290-2 of the raised railportions 280, 282 are closer to the leading edge 124-20 of the sliderbody than the trailing edge 294 of the raised center portion 284 to forman air bearing having raised bearing rails and raised center pad toreduce sensitivity to cross curve.

[0042] FIGS. 22-23 illustrate an alternate embodiment of a slider 120-22including a raised body 300 formed on a stepped bearing portion 302along a trailing edge portion 176-22 of the slider body. The steppedbearing portion 302 is elevated above a recessed bearing surface orregion 304 to form a raised bearing surface 306 elevated above a steppedbearing surface 308 and stepped bearing surface 308 elevated above therecessed bearing surface 304. The raised body 300 includes opposedraised rail portions 310, 312 and a raised center portion 314 tocooperatively formed raised bearing rails and a raised center pad on thetrailing edge portion 176-22 of the slider body without interveningrecessed surfaces or regions as previously described.

[0043] In the illustrated embodiment, the raised rail portions 310, 312are generally “U” shaped and are positioned on opposed sides of theraised center portion 314 forming the raised center pad of the airbearing. In the illustrated embodiment, the stepped bearing portion 302is formed along a center portion of the slider body between opposed sideportions. As shown, the air bearing includes opposed recessed cavities316, 318 on opposed sides of the stepped bearing portion 302 to formrecessed bearing surfaces 304-1, 304-2 below the stepped bearing surface308.

[0044] The raised rail portions 310, 312 include a leading edge 320-1,320-2 and a trailing edge 322-1, 322-2 and the raised center portion 314includes a leading edge 324 and trailing edge 326. As shown, the leadingedges 320-1, 320-2 of the raised rail portions 310, 312 are closer tothe leading edge 124-22 of the slider body than the leading edge 324 ofthe raised center portion 314. As shown, the trailing edges 322-1, 322-2of the raised rail portions 310, 312 are closer to the leading edge124-22 of the slider body than the trailing edge 326 of the raisedcenter portion 314 to form an air bearing having a raised body 300including raised bearing rails and a raised center pad to reducesensitivity to cross curve as described. In the embodiments described,the raised, stepped and recessed surfaces are formed using multiplemasking and etching steps to form the multiple surface tiers. Theillustrated embodiment includes stepped rails portions 328, 329 alongopposed sides 144-22, 146-22 of the slider. In an alternate embodiment,an etched or recessed cavity can be formed in a center portion ofstepped bearing portion 302.

[0045] FIGS. 24-25 illustrate a prior art slider embodiment wherebearing rails 330, 332 including raised and stepped bearing surfaces areformed along or proximate to opposed sides 144-24, 146-24 of the sliderbody and center pad 334 including raised and stepped bearing surfaces isformed along a center portion of the slider body. As shown, the rails330, 332 and center pad 334 are separated by a recessed cavity or region336 to provide independent bearing surfaces. In contrast as illustratedin FIGS. 26-27, the slider includes raised rail bodies 340, 342 and araised center body 344 formed on a stepped bearing surface 346 to formcooperating raised bearing surfaces 348-1, 348-2, 348-3 pressurizedrelative to the stepped bearing surface 346 which as illustrated in FIG.28 provides less sensitivity to cross curve since milling deformationsfor the air bearing structure deform in one plane as opposed todeforming in multiple planes.

[0046]FIG. 28 generally illustrates PTFH for different cross curves(cc=0.1 illustrated at column 350, cc=0.3 illustrated at column 352, andnominal illustrated at column 354) for different radial positions (innerdiameter ID illustrated at row 356, middle diameter MD illustrated atrow 358 and outer diameter OD illustrated at row 360) for the prior artslider embodiment 120-24 of FIGS. 24-25 and slider embodiment 120-26 ofFIGS. 26-27. As shown, PTFH for the slider 120-26 embodiment of FIGS.26-27 varied less relative to cc at different radial head positionsproviding less sensitivity to cross curve than the prior art sliderembodiment 120-24 of FIGS. 24-25.

[0047] FIGS. 29-30 illustrate an alternate embodiment of a slider 120-29having cooperating bearing surfaces as shown. As shown, the slider body120-29 includes opposed raised rail bodies 370, 372 and raised centerbody 374 formed on an integral stepped portion 378 forming raisedbearing surfaces 380-1, 380-2, 380-3 and stepped bearing surface 382. Inthe embodiment illustrated, the slider body includes a recessed cavity384 along an intermediate center portion of the slider body. The raisedrail bodies 370, 372 are formed proximate to opposed sides 144-29,146-29 of the slider body to form raised bearing rails and the raisedcenter body 374 is formed proximate to the center portion to form araised center pad. As shown the stepped portion is configured tointerface with the raised rail bodies and center body to providecooperating raised bearings surfaces as described.

[0048] An air bearing for a slider including cooperating raised bearingsurfaces or portions (such as 214-1, 214-2, 280, 282, 284) along atrailing edge portion 176 of the slider. The cooperating raised bearingsurfaces (such as 214-1, 214-2, 280, 282, 284) are formed on a steppedbearing surface or portion (such as 216, 272) which is elevated above arecessed bearing surface (such as 218, 274). The cooperating raisedbearing surfaces or portions form raised bearing rails or rails portionsor a raised center pad or raised center pad portion on the steppedbearing surface (such as 216, 272) to reduce cross curve sensitivity.

[0049] It is to be understood that even though numerous characteristicsand advantages of various embodiments of the invention have been setforth in the foregoing description, together with details of thestructure and function of various embodiments of the invention, thisdisclosure is illustrative only, and changes may be made in detail,especially in matters of structure and arrangement of parts within theprinciples of the present invention to the full extent indicated by thebroad general meaning of the terms in which the appended claims areexpressed. For example, the particular elements may vary depending onthe particular application while maintaining substantially the samefunctionality without departing from the scope and spirit of the presentinvention. In addition, although the preferred embodiment describedherein is directed to a particular data storage system, it will beappreciated by those skilled in the art that the teachings of thepresent invention can be applied to other data storage systems, withoutdeparting from the scope and spirit of the present invention.

What is claimed is:
 1. A head comprising: a slider body including aleading edge, a trailing edge and opposed sides; at least one transducerelement proximate to the trailing edge of the slider body; and an airbearing including a stepped bearing surface elevated above a recessedbearing surface and a plurality of raised bearing surfaces elevatedabove the stepped bearing surface and the air bearing including atrailing edge portion and the trailing edge portion including a steppedbearing portion forming the stepped bearing surface and the steppedbearing portion including a plurality of raised bodies on the trailingedge portion forming the plurality of raised bearing surfaces elevatedabove the stepped bearing surface along the trailing edge portion of theslider body.
 2. The head of claim 1 wherein the plurality of raisedbodies form opposed raised bearing rails.
 3. The head of claim 1 whereinthe plurality of raised bodies form a raised center pad and opposedraised bearing rails.
 4. The head of claim 1 wherein the plurality ofraised bodies are generally “U” shaped.
 5. The head of claim 2 whereinthe opposed raised bearing rails are generally formed along a centerportion of the slider body between the opposed sides of the slider body.6. The head of claim 3 wherein the opposed raised bearing rails and theraised center pad are generally formed along a center portion of theslider body between the opposed sides of the slider body.
 7. The head ofclaim 1 wherein the slider body includes a center portion and opposedside portions and the plurality of raised bodies are generally formedalong the center portion and the air bearing further including aplurality of recessed cavities formed on the opposed side portions. 8.The head of claim 1 wherein the slider body includes a center portionand opposed side portions and the stepped bearing portion is generallyformed along the center portion and includes a recessed cavity formedtherein between the opposed side portions.
 9. The head of claim 1wherein the plurality of raised bearing surfaces include a raisedbearing surface along a leading edge portion of the slider body and thestepped bearing portion having the plurality of raised bodies formedthereon extends from the raised bearing surface along the leading edgeportion proximate to the trailing edge of the slider.
 10. The head ofclaim 9 wherein the stepped bearing portion having the plurality ofraised bodies formed thereon includes a recessed cavity formed therein.11. A slider comprising: a slider body including a leading edge, atrailing edge, opposed sides and an air bearing; a stepped bearingportion elevated above a recessed bearing surface; and raised bearingsurface means on the stepped bearing portion including multiple raisedrail portions forming opposed side rails for the air bearing on thestepped bearing portion for cooperatively pressurizing the opposed siderails of the air bearing to reduce cross curve sensitivity.
 12. Theslider of claim 11 wherein the raised bearing means on the steppedbearing portion includes a raised center pad portion between themultiple raised rail portions.
 13. The slider of claim 11 wherein themultiple raised rail portions are “U” shaped.
 14. The slider of claim 11wherein the stepped bearing portion is formed along a center portion ofthe slider body between opposed side portions.
 15. A head comprising: aslider body including a leading edge, a trailing edge and opposed sides;at least one transducer element proximate to the trailing edge of theslider body; an air bearing including a stepped bearing surface elevatedabove a recessed bearing surface and a raised bearing surface elevatedabove the stepped bearing surface and the air bearing including atrailing edge portion and the trailing edge portion including a steppedbearing portion forming the stepped bearing surface and the steppedbearing portion including a raised body on the trailing edge portionincluding a raised center pad portion and opposed raised rail portionsforming the raised bearing surface elevated above the stepped bearingsurface along the trailing edge portion of the slider body.
 16. The headof claim 15 wherein the slider body includes a center portion andopposed side portions and the stepped bearing portion is formed alongthe center portion of the slider body between the opposed side portions.17. The head of claim 16 and wherein the opposed side portions include arecessed cavity forming a plurality of recessed bearing surfaces on theopposed side portions of the slider body.
 18. The head of claim 15wherein the stepped bearing portion includes a recessed cavity formedtherein to form a negative pressure pocket.
 19. The head of claim 15wherein the opposed rail portions are generally “U” shaped.
 20. The headof claim 15 wherein the opposed raised rail portions include a leadingedge and a trailing edge and the raised center pad portion includes aleading edge and a trailing edge and the leading edges of the raisedrail portions are positioned closer to the leading edge of the sliderbody than the leading edge of the center pad portion and the trailingedges of the raised rail portions are positioned closer to the leadingedge of the slider body than the trailing edge of the center padportion.